It is due to supply the 945MW Gennaker wind farm with 103 of its turbines with 167-metre rotors and power ratings of 9MW.
The European turbine maker will also service the turbines for 20 years.
It aims to start construction and complete installation of the Baltic Sea project in 2026.
The agreement remains subject to certain conditions, including the confirmation of the grid connection date. This is expected in the second half of the 2023 calendar year.
Wpd has started main soil investigation at each turbine location, and is currently tendering for other main components and installation vessels for Gennaker.
Germany aims to have 30GW of offshore wind capacity by 2030, 40GW by 2035 and 70GW by 2045.
Siemens Gamesa is also due to supply turbines to Wpd offshore wind farms in Germany, Taiwan and France.